It is well known that in many practical applications it is desirable to combine light from multiple light sources into one single beam. Of special interest is application of semiconductor-based light sources, such as laser diodes and light emitting diodes (LEDs). Even with recent progress in semiconductor technologies and advances toward more powerful LED designs, many applications still require the combined light output from a plurality of sources to achieve desirable luminous flux and/or color combinations. The dominant state-of-the-art solution is based on the use of an array of multiple individual peripheral optical elements described, for example, in U.S. Pat. Nos. 5,369,659 and 5,592,578. Unfortunately, these devices are expensive, bulky, cumbersome, require fine optical tuning and correction, and are not suitable for mass production.
Accordingly it would be desirable to have a luminaire which uses multiple light sources but produces an output beam collimated by a single set of optics, and which is compact and inexpensive.